Oh I'm all too familiar with many of your local gym's methods of measuring BF. I've PT'd at local gyms for several years. Now I'm private. Most of the PT's at many gym's don't have a clue on how to properly and accurately take measurements. In fact many PT's at your local L.A. fitness or 24 hour don't have a clue on anything at all, lol. Do you recall how many sites they used? Hopefully they performed the 7 site skin cal test. If they did it correctly then they hit all sites once and then again, and if they are within 1mm of each other (each other being the two measurements at the same site) good, but if they aren't a 3rd pinch is required. Also, look into Bodpod.
http://www.bodpod.com/clients. Accurate as shit. Keep up the good work..